Abstract 1234
Background
Gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) is a poorly differentiated grade 3 neuroendocrine neoplasm, of which the overall survival is poor with limited treatment options. Immune checkpoint related therapy such as PD-1 blocking has successfully been used in some solid tumor treatment. In this study, we investigated the infiltration of immune-cells and PD-1/PD-L1 blockade biomarkers to improve understanding of the tumor immune microenvironment in GEP-NEC.
Methods
Stromal and tumor cells expressing CD3, CD8 and CD68 protein were assessed in 32 cases of GEP-NEC by immunohistochemistry. Their tumor mutational burden (TMB) and microsatellite instability (MSI) were measured by gene sequencing. Software mSINGS MSIsensor and MSIseq were used to evaluate MSI and MSI status was set when more than two software showed the MSI. The Mann-Whitney U test and Kruskal-Wallis test were used to analyze the correlation of markers expression with clinicopathological parameters. Kaplan -Meier curves were applied in survival analyses.
Results
In the study, 65.6% of the patients were male and the median age was 65. The predominant primary sites were stomach (66%) and pancreas (19%). High infiltration (more than 25% stromal area infiltration) of CD3, CD8 and CD68 immune cells were found in 84%, 47% and 81% of the patients, respectively. High expression of CD3 correlated with high expression of CD8 and CD68 (p < 0.05). Average of TMB was 5.84 mutations per megabase. 57% of the patients were classified as having intermediate TMB (5-15 mutations/megabase) with the remaining classified as having low TMB (0-5 mutations/megabase). None of the patients was in MSI status under our evaluation. Among the baseline characteristics, patients in stage IV of TNM showed lower CD8 expression (p < 0.05). No significant association was observed between the investigated markers and survival.
Conclusions
The study contributes to the understanding of immune microenvironment of GEP-NEC. The association of clinicopathological features with PD-1/PD-L1 blockade biomarkers and immune cells in GEP-NEC were explored. This understanding should help to improve predictions of the impact of the PD-1/PD-L1 pathway in GEP-NEC patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Chinese Academy of Medical Sciences (CAMS) Initiative for innovative Medicine (CAMS-I2M) 2017-I2M-1-001.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5134 - Early prediction of the platinum-resistant relapse risk using the CA125 modeled kinetic parameter KELIM: a pooled analysis of AGO-OVAR 7 & 9; ICON 7 (AGO/GINECO/ MRC CTU/GCIG trials).
Presenter: OLIVIER COLOMBAN
Session: Poster Display session 2
Resources:
Abstract
4410 - Mirvetuximab soravtansine, a folate receptor alpha (FRa)-targeting antibody-drug conjugate (ADC), in combination with carboplatin and bevacizumab: Initial results from a Phase 1b study in patients (pts) with ovarian cancer
Presenter: David Omalley
Session: Poster Display session 2
Resources:
Abstract
5077 - Response to Pegylated Liposomal Doxorubicin (PLD) and Weekly Paclitaxel (wpac) in Platinum Resistant (PR) Ovarian Cancer (OC) by BRCA mutation status
Presenter: Louise Bremer
Session: Poster Display session 2
Resources:
Abstract
3483 - Impact of prior pegylated liposomal doxorubicin (PLD) treatment in recurrent ovarian cancer (ROC): Sub-group analysis from a randomized, open-label study comparing trabectedin (T) and PLD versus PLD alone in ROC (ET743-OVC-3006)
Presenter: Bradley Monk
Session: Poster Display session 2
Resources:
Abstract
5423 - OCTAVE - A phase I study of enadenotucirev, an oncolytic group B adenovirus, in combination with weekly paclitaxel in platinum-resistant epithelial ovarian cancer
Presenter: Iain McNeish
Session: Poster Display session 2
Resources:
Abstract
1385 - Phase I study of low dose whole abdominal radiation therapy (LDWART) in combination with weekly paclitaxel (wP) for platinum resistant ovarian cancer (PROC)
Presenter: Natalie Ngoi
Session: Poster Display session 2
Resources:
Abstract
2090 - Phase 1b/2a study assessing the safety and efficacy of adding AL3818 (Anlotinib) to standard platinum-based chemotherapy in subjects with recurrent or metastatic endometrial, ovarian or cervical carcinoma
Presenter: David Miller
Session: Poster Display session 2
Resources:
Abstract
1960 - Phase I Study of Intraperitoneal TRX-E-002-1 in Subjects with Persistent or Recurrent Ovarian, Fallopian Tube or Primary Peritoneal Cancer: Three-month Follow-up Results of the Dose Escalation Phase
Presenter: Jermaine Coward
Session: Poster Display session 2
Resources:
Abstract
4288 - Hybrid capture-based genomic profiling of circulating tumor DNA (ctDNA) from patients with ovarian cancer
Presenter: Mi Yang
Session: Poster Display session 2
Resources:
Abstract
3433 - Tumor Microvessel Density for predicting Nintedanib activity: data from the randomized CHIVA trial (a GINECO study)
Presenter: Maud Villemin
Session: Poster Display session 2
Resources:
Abstract